I actually missed this report a few days ago, partially because I thought the February report had already been released a few weeks back; it turns out I was thinking of January's.

For January I overshot the mark a bit, but for February my projections were pretty much bang-on target, with an net incrase of 12.65 million Medicaid/CHIP enrollees to date thanks to the ACA. But wait, you're saying: The report says the net gain is only 11.7 million!

These enrollment counts are in addition to the enrollment increases from the nearly 950,000 individuals who gained coverage as a result of the Affordable Care Act before open enrollment began. Seven states implemented an “early option” to expand Medicaid coverage to adults with incomes up to 133 percent of the FPL between April 1, 2010 and January 1, 2014, using new state plan authority provided by the Affordable Care Act or a demonstration under section 1115 of the Social Security Act building upon that authority.

Those would be the 950,000 "bulk transfers" which make up the red band in the Medicaid graph.

Over 70.5 million individuals were enrolled in Medicaid and CHIP in February 2015. This enrollment count is point-in-time (on the last day of the month) and includes all enrollees in the Medicaid and CHIP programs who are receiving a comprehensive benefit package.

561,609 additional people were enrolled in February 2015 as compared to January 2015 in the 51 states that reported comparable February and January 2015 data.

Looking at the additional enrollment since October 2013 when the initial Marketplace open enrollment period began, among the 49 states reporting both February 2015 enrollment data and data from July-September of 2013, over 11.7 million additional individuals are enrolled in Medicaid and CHIP as of February 2015, an approximately 20.3 percent increase over the average monthly enrollment for July through September of 2013.9 (Connecticut and Maine are not included in this count.)

Add on the other 950K and you're up to a net increase of 12.65 million enrolled in Medicaid/CHIP since the ACA was signed into law. Whether you consider this a good or bad thing, of course, depends on your POV.

On that same note, here's the Expansion State vs. Non-Expansion State divide:

Among states that had implemented the Medicaid expansion and were covering newly eligible adults in February 2015, Medicaid and CHIP enrollment rose by almost 27 percent compared to the July-September 2013 baseline period, while states that have not, to date, expanded Medicaid reported an increase of over 8 percent over the same period.

The 8% Medicaid/CHIP enrollment increase in NON-expansion states is mostly due to the "woodworker effect", of course (which also explains a portion of the increase in expansion states as well).

Of course, the Graph itself doesn't stop at the end of February; my own projections actually have the net gain in Medicaid/CHIP enrollments up to 13.4 million as of early May (12.4 million if you don't include the 950K "pre-expansion" folks).